What is the driving force for the movement of materials in the phloem of plants?

Question

Quizplus · Accepted Answer

The driving force for the movement of materials in the phloem of plants is a difference in osmotic water potential between the source (where sugar is produced through photosynthesis) and the sink (where sugar is needed for growth and metabolism). This creates a pressure gradient that moves the sugar, along with water and other solutes, from the source to the sink. Gravity, root pressure, transpiration, and adhesion may have some influence, but they are not the primary driving force for phloem transport.

What Is the Driving Force for the Movement of Materials